The present invention relates in general to frame structures, and, more particularly, to space frame apparatuses, and the process for manufacturing same, wherein such a space frame apparatus is used in the construction of various vehicles, such as automotive and aviation vehicles, and wherein the space frame apparatus is intended to structurally bear a substantial load of such a vehicle when fully assembled.
Space frame structures for use in the construction of vehicles have been know in the art for several years. Typically, such space frames have been constructed from a plurality of individual aluminum alloy extrusions which are joined together at nodes generally fabricated from cast or wrought shapes. Each of the nodes generally comprise three to four connecting regions which each fit into the hollow sections of the ends of corresponding ones of the individual extrusions. The ends of the extrusions may then be secured to the respective nodes through welding or adhesive bonding. Two examples of such a node-type construction can be found in Browning, U.S. Pat. No. 4,735,355, and, in an article in the May, 1991 Materials Engineering Magazine, referring to "Automotive Aluminum."
Although use of nodes for attachment of individual, segmented extrusions, have indeed been utilized, such a construction has resulted in concerns relative to the structural integrity of such connections--especially inasmuch as both welds and adhesive bonding have a tendency to fatigue upon exposure of excessive vibration and stress typically imparted to such connections during normal operation of a vehicle employing such a space frame structure. Furthermore, when nodes, or the like, are used in a space frame, the space frame requires numerous individual extruded frame segments and numerous nodes for connection therewith. Accordingly, the costs associated with such a construction, coupled with concerns from a structural perspective, have resulted in the need for a better alternative.
Although the above-identified prior art utilizes a plurality of individual, segmented frame portions in combination with connecting nodes, other prior art space frames have been constructed from continuous frame portions, without reliance upon nodes. One example of such prior art is Malmurno, U.K. Pat. Apln. GB 2 131 361 A. Although Malmurno does utilize continuous frame portions, the cross-members which maintain the outer frame portions in an erected orientation appear to be merely welded to the frame. Accordingly, the same concerns pertaining to fatigue of the connection between the cross-member and the outer frame portions persist--even without the use of nodes.
Although prior art space frames disclose continuous outer frame portions, as well as means for connecting cross-members to the frames, none of such prior art teaches, much less discloses, one or more continuous outer frame portions which include preliminarily pre-softened regions, which are softened through localized heat induction, and, wherein the one or more continuous outer frame portions are then bendable to varying radii in any predetermined direction relative to a particular vehicle configuration. Furthermore, none of such prior art teaches, much less discloses attachment of cross-members to the continuous outer frame portions of a space frame wherein the respective ends of the cross-members are insertable into corresponding slots within the continuous frame portions, and wherein the ends of the cross-members include a flange and collar portion each formed upon softening through localized heat induction and then deformation--for purposes of securely pinching the cross-member to the inner and outer peripheral surfaces of the corresponding slots.
It is thus an object of the present invention to provide a space frame apparatus constructed from one or more continuous outer frame portions which are secured in an erected orientation through cooperation with one or more cross-members--without reliance upon separate connecting elements, or nodes.
It is also an object of the present invention to provide a space frame apparatus wherein secured connection of the one or more cross-members to the one or more continuous outer frame portions is maintained by a compression fit between the flange and collar portion of the ends of the cross-members about the inner and outer peripheral surfaces of the corresponding slot shoulders, and wherein such flange and collar portions are formed by softening the distal and proximal ends of the cross-members through localized heat induction and then deforming same into such a flange and collar configuration.
It is still further an object of the present invention to provide a space frame apparatus wherein the one or more continuous outer frame portions are constructed from aluminum extrusions which have a plurality of predetermined areas pre-softened through localized heating so that continuous extrusions can be bent to varying predetermined radii in predetermined directions relative to a specific vehicle configuration, and wherein the bent regions are then allowed to harden toward their original hardness.
It is yet another object of the present invention to provide a space frame apparatus having superior structural integrity at the connecting joint between the cross-members and the continuous outer frame portions, and which can be manufactured at relatively low costs.
These and other objects of the present invention will become apparent in light of the present Specification, Claims and Drawings.